The point of this card isn't to play cards for free. It's that now your big spells only cost 2 mana and you can then build a board after. Twisting nether costs a lot of mana, and is pretty much your whole turn. So instead, twisting nether plus 6 free mana to do stuff with

so a 2 mana combo for a 2 mana boardclear and lose almost a third of your health

im not that sure if its playable, especially since health will matter a lot more, now that reno is out, even in aggro this could hurt a lot. if you have to clear the board so badly as aggro, you probably have lost anyways. In a few scenarios it could be good, but not enough to justify putting it in the deck i think

This card is just so pointless because of the 2 mana cost. You would never want to play a big spell after this for obvious reasons, and playing a low cost spell doesn't make sense since you're already spending 2 mana on this card..